Kudlow will help to craft Trump's policies and advise Trump on trade, taxes, and more as part of the White House staff.

The former Reagan White House and Bear Stearns economist expressed support for Trump during the 2016 campaign, primarily for his tax cut plan, but Kudlow hasn't always been kind to the president.

In 2015, prior to Trump's ascendancy, Kudlow repeatedly took shots at the then-candidate via Twitter.

During that time, Kudlow shared many articles attacking Trump, including one lambasting his immigration policy, one criticizing Trump's attacks on China's currency, and a piece by Jonah Goldberg in the conservative National Review titled, "No Movement That Embraces Trump Can Call Itself Conservative."

In fact, one tweet Kudlow shared even featured a GIF of Trump being body slammed during a WWE appearance with an image of Jeb Bush's face placed over the attacking wrestler's face:

More recently, Kudlow was highly critical of Trump's decision to impose new tariffs on imports of steel and aluminum.

On March 1, the day of Trump's tariff announcement, Kudlow shared a Wall Street Journal op-ed entitled "Trump's Tariff Folly," that called the move "the biggest policy blunder of his Presidency."

The next day, Kudlow shared his own op-ed with the tweet, "Larry Kudlow: Trump's tariffs a 'bad omen' and could cause 'major calamity'."

On March 8, Kudlow retweeted wealth manager David Bahnsen who endorsed a tweet calling Trump and "erratic POTUS" and attacking the tariffs.

Even as recently as Saturday, Kudlow tweeted another Journal op-ed lambasting the tariffs.

Kudlow was originally considered for the position as chair of the Council of Economic Advisers in the early days of the administration, but was passed over due to his disagreements with the president.